Washington: Former US National Security Adviser (NSA) Michael Flynn will be sentenced by the end of November, after it had been delayed four times since he pleaded guilty to lying to investigators last December, according to his defence team. The announcement, indicated in a court filing on Monday, suggests that Flynn's cooperation with Special Counsel Robert Mueller's ongoing Russia investigation will end soon, CNN reported.

Until three days ago, Flynn was the highest-ranking Trump associate cooperating with the probe into Russian interference in the 2016 presidential elections and its aftermath. On September 14, former Trump campaign chairman Paul Manafort pleaded guilty to two federal charges. He also agreed to fully cooperate with Mueller as well. Flynn admitted to lying about his communications with the Russian ambassador during Trump's presidential transition.

He also said he had lied to the Justice Department in 2017 about doing consulting work for the Republic of Turkey, according to his court filings. Flynn was also expected to corroborate details for investigators about other Trump campaign officials' interests in Russian policy pushes during the campaign and transition. According to a statement filed in court, Flynn conducted several calls with senior officials on the Trump transition team about his discussions with then-ambassador Sergey Kislyak related to US sanctions of Russia.

Since December 1, 2017, Flynn was required to cooperate with Mueller's office "fully, truthfully, completely and forthrightly", including speaking to law enforcement officials about what he knows and testifying before any grand juries and trials if needed.